Long Term Evolution Unlicensed (LTE-U) refers to deploying LTE in unlicensed spectrums to satisfy sharply increasing capacity demands of an LTE system and improve the use efficiency of unlicensed spectrums, and is one of possible important evolution directions of LTE and future wireless communication. When LTE-U is designed, it needs to consider about how to fairly and friendly contend with different systems such as Wireless Fidelity (WiFi) and radar and identical LTE-U systems for unlicensed spectrums to perform data transmission on a premise that LTE technical features are not influenced and are reserved as much as possible. According to the expression of 3GPP standard conference, an LTE-U system may also be called as an LTE Licensed Assisted Access (LAA) system. At present, modes for LAA/LTE-U to use unlicensed spectrums include Carrier Aggregation Supplemental Downlink (CA SDL), Carrier Aggregation Time Division Duplex (CA TDD) and Standalone modes, wherein CA SDL is a mainstream mode at present.
After an unlicensed carrier access point or base station preempts a resource at each time, a series of processes such as synchronization, downlink receiving, Channel State Information (CSI) measurement, uplink feedback and scheduling need to be performed, and this will occupy much time from several milliseconds to more than ten milliseconds. However, a maximum continuous occupation time length of unlicensed carriers which are under control is approximate tens of milliseconds, which are generally different in different regions. In other words, a quite large part of a time resource which is preempted by the unlicensed carrier access point or base station at each time is used for processing operations other than data sending, and this greatly reduces the spectrum use efficiency and performance of the system. However, no corresponding solution has been provided in the related technology on how to reduce the proportion of the overhead of the above-mentioned processes in the preempted resource.